title: Bacteria-derived DNA fragment in peritoneal dialysis effluent as a predictor of relapsing peritonitis.
abstract: OBJECTIVE
  Relapsing and recurrent peritonitis episodes are important causes of treatment failure in patients undergoing peritoneal dialysis (PD). This study explored whether the level of bacteria-derived DNA fragment in PD effluent predicts the development of relapsing or recurrent peritonitis.
  
  
  METHODS
  The study included 143 patients with PD peritonitis in a dialysis unit between September 2010 and December 2011. Every 5 days until antibiotic treatment ended, PD effluent was collected to determine bacteria-derived DNA fragment level, which is represented by the number of PCR cycles at which bacterial DNA could be detected. Patients were followed for the development of relapsing or recurrent peritonitis.
  
  
  RESULTS
  Thirty-nine patients were excluded because of immediate treatment failure or incorrect diagnosis. Of the other 104 patients, 15 (14.4%) developed relapsing peritonitis, 3 (2.9%) had recurrent peritonitis, and 5 (4.8%) had repeat episodes. Patients with relapsing or recurrent peritonitis episodes had significantly higher levels of bacterial DNA fragment in PD effluent than those without relapsing or recurrence, both 5 days before (31.9 ± 3.4 versus 34.3 ± 3.0 cycles; P=0.002) and on the day of (32.3 ± 2.6 versus 34.1 ± 1.7 cycles; P<0.001) completion of antibiotics. When bacterial DNA fragment detectable by 34 PCR cycles 5 days before the completion of antibiotics is used as the cutoff, it has a sensitivity of 88.9% and specificity of 60.5% for the prediction of relapsing or recurrent peritonitis.
  
  
  CONCLUSIONS
  Bacterial DNA fragment levels in PD effluent are significantly higher, both 5 days before and on the date of completion of antibiotics, among patients who subsequently develop relapsing or recurrent peritonitis than among those cured by antibiotics. Further studies are needed to validate these results and confirm the clinical utility of dialysate bacterial DNA fragment level.
authors.affiliation: Carol and Richard Yu Peritoneal Dialysis Research Centre, Department of Medicine & Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Cheuk-Chun
authors.initials: CC
authors.lastname: Szeto
authors.forename: Ka-Bik
authors.initials: KB
authors.lastname: Lai
authors.forename: Bonnie Ching-Ha
authors.initials: BC
authors.lastname: Kwan
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chow
authors.forename: Chi-Bon
authors.initials: CB
authors.lastname: Leung
authors.forename: Man-Ching
authors.initials: MC
authors.lastname: Law
authors.forename: Vincent
authors.initials: V
authors.lastname: Yu
authors.forename: Philip Kam-Tao
authors.initials: PK
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D004269:DNA, Bacterial / Q000302:isolation & purification*; D015314:Dialysis Solutions / Q000032:analysis*; D005260:Female; D005819:Genetic Markers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010538:Peritonitis / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012008:Recurrence; D021521:Ribotyping / Q000379:methods; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D015314:Dialysis Solutions; D005819:Genetic Markers; D012336:RNA, Ribosomal, 16S